Field of the Invention and Related Art
The present invention relates to a dielectric filter with an attenuation pole that is particularly adapted for use in an antenna of a mobile phone system.
There are many known techniques relating to a ceramic bandpass filter to be used in a mobile phone.
FIG. 1 shows a typical example of these techniques which comprises an integral dielectric single-block 101 (hereinafter referred to as simply the dielectric block), a plurality of resonators 102 extending from a top surface toward a bottom surface of the dielectric block 101, a plurality of adjusting patterns 103 provided over the top surface of the dielectric block 101, input and output electrodes 104 and metallized patterns 105 provided over side surfaces and the bottom surface of the dielectric block 101.
The inner conductors are formed within inner walls of the resonators 102.
These inner conductors are connected to the adjusting patterns 103 at the top surface of the dielectric block 101. The inner conductors are connected to the metallized patterns 105 at the bottom surface of the dielectric block 101. The metallized patterns 105 are grounded.